hurt finger, knuckle

About six months ago, I was rock climbing indoors.
I reached for a hold with my right hand quickly and smashed into another hold.
The impact hit the outsid eof my hand on the the pinkie knuckle.
I used to have a lot of pain.
It would be very painful if someone or something would barely hit it.
It has been feeling fine for about a month.
However, I went to a kickboxing lesson last night and it still hurts.
It is the same pain around the knuckle on my pinkie, like when you make a fist.
What is wrong?